Just recently had a problem after getting new tires and having dealer use Dyna Beads to balance trires. When the tires spin, the beads were forced into the valve stem causing the core to stick when using a gauge to check tire pressure. I had to return bike to dealer to have beads removed and tires re-balanced using weights. The service manager agreed that the beads did cause the valve to stick, thereby deflating the tire and did all the remedial work at no charge. He said he has been using beads for 3 years with no prior problems. Anyone out there with Dyna Beads in their tires should watch out for this potential problem.